1. Field of the Invention:
The present invention relates to a portable engine-operated electric generator having a unitary combination of an engine unit and a generator unit driven thereby, and more particularly to an improvement in the arrangement of such an engine unit and generator unit.
2. Description of the Relevant Art:
Portable engine-operated generators are required to have good sound insulation for engine sounds, to be capable of efficiently radiating generated heat, and, most of all, to be of good portability. Attempts to meet the above requirements by positioning an engine unit and a generator unit side by side are disclosed in Japanese Laid-Open Utility Model Publication No. 53-3302, Japanese Laid-Open Patent Publications Nos. 59-17097, 59-87225, and 59-170596, U.S. Pat. Nos. 4,595,841 and 4,608,946, for example. In each of the conventional arrangements shown in the latter four publications, the engine unit is located centrally, and a muffler is positioned on the same side as the generator unit with a carburetor and an air cleaner disposed on the same side as a recoil starter in opposite relation to the muffler. With this structure, the components are separated into heated and unheated components for increased cooling efficiency and good maintainability. However, the cylinder block of the engine unit, which is a heated component, and the carburetor and the air cleaner, which are unheated components, are disposed closely to each other, and hence no complete isolation has been accomplished between these heated and unheated components.
Japanese Laid-Open Patent Publications Nos. 59-39933 and 59-39934 disclose a portable engine-operated generator in which the output shaft of an engine unit and the input shaft of a generator unit are coupled to each other in vertical coaxial alignment, so that the engine unit and the generator unit are vertically arranged to reduce their area of projection as viewed in plan as much as possible. According to these conventional configurations, however, the height of the overall generator is increased making it unstable in use, and a carburetor is located near an engine cylinder block, thus still failing to provide desired separation between the unheated and heated components.